Liquid crystal displays (LCDs) generally display images by transmitting or blocking light through the action of liquid crystals. LCDs have been used in a variety of computing displays and devices, including notebook computers, desktop computers, tablet computing devices, mobile phones (including smart phones) automobile in-cabin displays, on appliances, as televisions, and so on. LCDs often use an active matrix to drive liquid crystals in a pixel region. In some LCDs, a thin-film transistor (TFT) is used as a switching element in the active matrix.
FIG. 1A illustrates a perspective view of a sample electronic device, such as a tablet computer. The electronic device includes a touch screen display 100 enclosed by a housing 138. The touch screen display 100A incorporates a cover glass 102 and an LCD 100B behind the cover glass 102, although alternative embodiments may employ an organic light-emitting display (OLED) layer instead of an LCD. The LCD 100B is not shown in FIG. 1A.